The term CCS refers to technologies for capturing CO2 that would otherwise be emitted to the atmosphere, and transporting it to a suitable location for permanent storage.

The related term Carbon Capture and Utilisation (CCU) refers to using the captured CO2 in other processes rather than sequestering it.

Sometimes CCU and CCS are grouped together as "CCUS".

Big sources of CO2 – and attractive targets for CCUS projects – are the burning of fuels containing carbon: fossil fuels such as coal, oil and natural gas, and Biofuels, (where it is referred to as BECCS - Bio-Energy with Carbon Capture and Storage). It can also be used where CO2 is emitted by other processes, such as cement, steel, fertiliser, and glass production.

How CCS works

Post-combustion capture

CO2 is captured from the flue gases of power stations, or other industrial processes such as manufacture of steel, cement, glass etc.

The most proven technologies are based on solvents such as Amines, which have been used successfully and safely for decades, although other technologies are under investigation and development.

Pre-combustion capture

In this technology a carbon-based fuel (e.g. coal or gas) is first processed to produce, typically, CO2 and Hydrogen. The CO2 is captured and the Hydrogen is used as fuel which can be burned cleanly.

Oxy-combustion

In post-combustion capture the concentration of CO2 in flue gases of, say, a power station, is typically around 4%. The flue gases also contain a lot of Nitrogen and its oxides (which can also be greenhouse gases), which came from the air which the fuel was burned in. In the oxy-combustion process oxygen is first separated from the air and used to burn the fuel. The flue gases then contain no Nitrogen or its oxides, and a much higher proportion of CO2 which is easier to capture.

The Allam cycle takes this further and uses the CO2-rich flue gas directly as a working fluid to drive a turbine, rather than heating water to generate steam to drive turbines.

Expert assessments

The mandate of the report [] included the assessment of the technological maturity, the technical and economic potential to contribute to mitigation of climate change, and the costs. It also included legal and regulatory issues, public perception, environmental impacts and safety as well as issues related to inventories and accounting of greenhouse gas emission reductions. This report primarily assesses literature published after the Third Assessment Report (2001) on CO2 sources, capture systems, transport and various storage mechanisms. It does not cover biological carbon sequestration by land use, land use change and forestry, or by fertilization of oceans. The report builds upon the contribution of Working Group III to the Third Assessment Report Climate Change 2001 (Mitigation), and on the Special Report on Emission Scenarios of 2000, with respect to CO2 capture and storage in a portfolio of mitigation options. It identifies those gaps in knowledge that would need to be addressed in order to facilitate large-scale deployment.

Current short-, medium- and long-term projections for global energy demand still point to fossil fuels being combusted in quantities incompatible with levels required to stabilise greenhouse gas (GHG) concentrations at safe levels in the atmosphere. All technologies along the CCS chain are known. They have been in operation in various industries for decades, although at relatively small scale. However, for the sole purpose of limiting climate change, these technologies have been put together in industrial scale (>1Mt CO2 captured and stored per year) in only a small number of installations.

General resources

Since 1997, Department of Energy (DOE) Office of Fossil Energy’s Carbon Storage program has significantly advanced the carbon capture and storage (CCS) knowledge base through a diverse portfolio of applied research projects. The portfolio includes industry cost-shared technology development projects, university research grants, collaborative work with other national laboratories, and research conducted in-house through the National Energy Technology Laboratory’s (NETL) Research and Innovation Center.

The Carbon Storage Program is administered by the FE Office of Clean Coal and Carbon Management. The primary focus of the Program going forward is on early-stage R&D to develop coupled simulation tools, characterization methods, and monitoring technologies that will improve storage efficiency, reduce overall cost and project risk, decrease subsurface uncertainties, and identify ways to ensure that operations are safe, economically viable, and environmentally benign.

Key Program goals include:

Determining the CO2 storage resource potential of on and offshore oil, gas, and saline bearing formations

Improving carbon storage efficiency and security by advancing new and early-stage monitoring tools and models

There are two primary types of carbon sequestration. Our program focuses on carbon dioxide capture and storage, where carbon dioxide is captured at its source (e.g., power plants, industrial processes) and subsequently stored in non-atmospheric reservoirs (e.g., depleted oil and gas reservoirs, unmineable coal seams, deep saline formations, deep ocean). The other type of carbon sequestration focuses on enhancing natural processes to increase the removal of carbon from the atmosphere (e.g., forestation).

Carbon sequestration can be defined as the capture and secure storage of carbon that would otherwise be emitted to, or remain, in the atmosphere. The focus of this paper is the removal of CO2 directly from industrial or utility plants and subsequently storing it in secure reservoirs. We call this carbon capture and storage (CCS). The rationale for carbon capture and storage is to enable the use of fossil fuels while reducing the emissions of CO2 into the atmosphere, and thereby mitigating global climate change. The storage period should exceed the estimated peak periods of fossil fuel exploitation, so that if CO2 re-emerges into the atmosphere, it should occur past the predicted peak in atmospheric CO2 concentrations. Removing CO2 from the atmosphere by increasing its uptake in soils and vegetation (e.g., afforestation) or in the ocean (e.g., iron fertilization), a form of carbon sequestration sometimes referred to as enhancing natural sinks, will only be addressed briefly.

One of the technologies highlighted in the [IPCC SR15] report is bioenergy with carbon capture and storage (BECCS). The Institution’s Engineering Policy Adviser, Matt Rooney, examines this controversial approach to climate change mitigation.

Post-combustion capture

This paper examines thermal efficiency penalties and greenhouse gas as well as other pollutant emissions associated with pulverized coal (PC) power plants equipped with postcombustion CO2 capture for carbon sequestration. We find that, depending on the source of heat used to meet the steam requirements in the capture unit, retrofitting a PC power plant that maintains its gross power output (compared to a PC power plant without a capture unit) can cause a drop in plant thermal efficiency of 11.3–22.9%-points. This estimate for efficiency penalty is significantly higher than literature values and corresponds to an increase of about 5.3–7.7 US¢/kWh in the levelized cost of electricity (COE) over the 8.4 US¢/kWh COE value for PC plants without CO2 capture. The results follow from the inclusion of mass and energy feedbacks in PC power plants with CO2 capture into previous analyses, as well as including potential quality considerations for safe and reliable transportation and sequestration of CO2. We conclude that PC power plants with CO2 capture are likely to remain less competitive than natural gas combined cycle (without CO2 capture) and on-shore wind power plants, both from a levelized and marginal COE point of view.

Allam Cycle

Demonstration of the Allam Cycle: An Update on the Development Status of a High Efficiency Supercritical Carbon Dioxide Power Process Employing Full Carbon Capture
by Rodney Allam, Scott Martin, Brock Forrest, Jeremy Fetvedt, Xijia Lu, David Freed, G. William Brown Jr., Takashi Sasaki, Masao Itoh, James Manning
in Energy Procedia / 13th International Conference on Greenhouse Gas Control Technologies, GHGT-13, 14-18 November 2016, Lausanne, Switzerland
in 2017
[[article]
[PDF]

The Allam cycle is a novel CO2, oxy-fuel power cycle that utilizes hydrocarbon fuels while inherently capturing approximately 100% of atmospheric emissions, including nearly all CO2 emissions at a cost of electricity that is highly competitive with the best available energy production systems that do not employ CO2 capture. The proprietary system achieves these results through a semi-closed-loop, high-pressure, low-pressure-ratio recuperated Brayton cycle that uses supercritical CO2 as the working fluid, dramatically reducing energy losses compared to steam- and air-based cycles. In conventional cycles, the separation and removal of low concentration combustion derived impurities such as CO2 results in a large additional capital cost and increased parasitic power. As a result, removal in conventional cycles can increase the cost of electricity by 50% to 70%. The compelling economics of the Allam Cycle are driven by high target efficiencies, 59% net for natural gas and 51% net for coal (LHV basis) while inherently capturing nearly 100% CO2 at pipeline pressure with low projected capital and O&M costs. Additionally, for a small reduction in performance the cycle can run substantially water free. The system employs only a single turbine, utilizes a small plant footprint, and requires smaller and fewer components than conventional hydrocarbon fueled systems. The Allam Cycle was first presented at GHGT-11. Since then, significant progress has been made, including detailed system design, component testing and the construction of a 50 MWth demonstration plant commencing in Q1 2016 and now entering commissioning as of Q4 2016. This paper will review the development status of the Allam Cycle; for the demonstration plant, the construction and commissioning status, schedule, key components, layout, and detailed design; turbine design, manufacturing status; development of a novel dynamic control system and control simulator for the demonstration plant; and other key aspects of the cycle. It will provide an update on the progress of the gasified solid fuel Allam Cycle and then address the overall Allam Cycle commercialization program, benefits and applications, and the expected design of the natural gas 300 MWe commercial NET Power plant projected for 2020.

NET Power, a utility set up in 2010, is building zero-carbon natural gas-fired power plants in the United States and abroad and plans on making them cheap enough in the future to compete with traditional fossil fuel power plants.

Forbes’s Jeff McMachon reports that the company revealed its multiple projects, which involve carbon capture, at a workshop organized by the National Laboratories of Sciences, Engineering, and Medicine.

"We have multiple 300MW-scale commercial projects in development," Adam Goff, a senior executive at NET Power’s parent company, 8 Rivers Capital, said. "None of them are announced yet, but we’ve got a couple in the U.S. and then some in Canada, Asia-Pacific and the Middle East and Europe—the regions of the world where we have interest in developing these projects."

According to its website, NET Power generates cheaper electricity than traditional fossil fuel-powered facilities by utilizing a proprietary thermodynamic cycle called the Allam Cycle. The cycle, the company said, allows for the elimination of all emissions, including those of carbon dioxide.

Any carbon dioxide produced in the process of burning the natural gas to power the turbines is in the form of a “high-pressure, high-quality byproduct, ready for pipeline transportation and storage.” Moreover, the company uses this high-pressure CO2 instead of the heat used in traditional power plants to spin the turbine.

In the past decade, an ambitious — but still mostly hypothetical — technological strategy for meeting our global climate goals has grown prominent in scientific discussions. Known as “negative emissions,” the idea is to remove carbon dioxide from the air using various technological means, a method that could theoretically buy the world more time when it comes to reducing our overall greenhouse-gas emissions. Recent models of future climate scenarios have assumed that this technique will be widely used in the future. Few have explored a world in which we can keep the planet’s warming within at least a 2-degree temperature threshold without the help of negative-emission technologies. But some scientists are arguing that this assumption may be a serious mistake.

In a new opinion paper, published Thursday in the journal Science, climate experts Kevin Anderson of the University of Manchester and Glen Peters of the Center for International Climate and Environmental Research have argued that relying on the uncertain concept of negative emissions as a fix could lock the world into a severe climate-change pathway. “[If] we behave today like we’ve got these get-out-of-jail cards in the future, and then in 20 years we discover we don’t have this technology, then you’re already locked into a higher temperature level,” Peters said. Many possible negative-emission technologies have been proposed, from simply planting more forests (which act as carbon sinks) to designing chemical reactions that physically take the carbon dioxide out of the atmosphere. The technology most widely included in the models is known as bioenergy combined with carbon capture and storage, or BECCS.

First, the sheer amount of bioenergy fuel required to suit the models’ assumptions already poses a problem, Peters told The Washington Post. Most of the models assume a need for an area of land at least the size of India, he said, which prompts the question of whether this would reduce the area available for food crops or force additional deforestation, which would produce more carbon emissions.

despite millions in government investment, “carbon capture and storage,” as it’s called, has largely flopped in California. Faced with high costs and public opposition, several projects have failed to move beyond the planning stage.

Southern Co.’s $6.9 billion “clean coal” power plant in Mississippi produced electricity for the first time. The Kemper station used synthetic natural gas, converted from Mississippi lignite coal, to produce its first batch of power, Southern’s Mississippi Power utility said in a statement Wednesday. The generation brings Southern a step closer to placing the plant into full commercial operations after years of delays and cost overruns. Once in service, it’ll be the first large-scale power plant in the U.S. to gasify coal and capture carbon before it’s released into the atmosphere. The U.S. Department of Energy provided $245 million in a grants for the project, which the coal industry had been banking on as a potential way toward developing cleaner-burning technologies as pollution limits take hold.

The first large scale U.S. “clean coal” facility was declared operational Tuesday — by the large energy firm NRG Energy and JX Nippon Oil & Gas Exploration Corp. Their Petra Nova project, not far outside of Houston, captured carbon dioxide from the process of coal combustion for the first time in September, and has now piped 100,000 tons of it from the plant to the West Ranch oil field 80 miles away, where the carbon dioxide is used to force additional oil from the ground. The companies say that the plant can capture over 90 percent of the carbon dioxide released from the equivalent of a 240 megawatt, or million watt, coal unit, which translates into 5,000 tons of carbon dioxide per day or over 1 million tons per year. They’re calling it “the world’s largest post-combustion carbon capture system.”

But there is another coal plant near completion in the United States that will also capture carbon dioxide — but using a very different approach. It’s the Kemper Plant, being operated by Mississippi Power, a subsidiary of Southern Co., and expected to be operational Jan. 31. This plant has been designed to turn lignite, a type of coal, into a gas called syngas, stripping out some carbon dioxide in the process. The syngas is burned for electricity and the CO2 is then again shipped to an oil field to aid in additional oil recovery. Thus, at Petra Nova the capturing of carbon occurs after the coal has been burned — or “post-combustion” — whereas at Kemper, it happens beforehand.

UK

The world’s first commercial scale, full chain, carbon capture and storage coal-fired power plant is being proposed by developer, Capture Power. The White Rose Carbon Capture and Storage Project (White Rose CCS Project), will comprise a state-of-the-art coal-fired power plant that is equipped with full carbon capture and storage technology. The project is intended to prove CCS technology at commercial scale and demonstrate it as a competitive form of low carbon power generation and as an important technology in tackling climate change. It will also play an important role in establishing a CO2 transportation and storage network in the Yorkshire and Humber area.

News: Government withdraws CCS Commercialisation Programme 25/11/2015

Today, following the Chancellor’s Autumn Statement, HM Government confirmed that the £1 billion ring-fenced capital budget for the Carbon Capture and Storage (CCS) Competition is no longer available. Commenting on the news that the budget for the CCS competition is no longer available, Leigh Hackett, CEO of Capture Power, said: “We are surprised and very disappointed by the Government’s decision to cancel the £1bn CCS Commercialisation Programme more than three years into the competition. “It is too early to make any definitive decisions about the future of the White Rose CCS Project, however, it is difficult to imagine its continuation in the absence of crucial Government support.”

The government’s cancellation of a pioneering £1bn competition to capture and store carbon emissions may have pushed up the bill for meeting the UK’s climate targets by £30bn, according to a report from the UK’s official spending watchdog. The National Audit Office (NAO) report, published on Wednesday, says the move has delayed by a decade the deployment of carbon capture and storage (CCS) technology in the UK, which takes emissions from power stations and industry and buries them so they do not contribute to global warming. The Treasury was warned by officials about the cost implications and that the last-minute cancellation could cause damage to the government’s reputation with industry and the international community. But the government, amid cuts to spending, decided the competition was aiming to deliver CCS before it was necessary and cost-efficient to do so. Both the UK government’s official advisers, the Committee on Climate Change (CCC), and the UN’s climate panel have warned that the cost of tackling climate change will be doubled without CCS, as more expensive alternatives are needed instead. The UK is well placed to develop CCS, with access to depleted oil and gas fields in the North Sea to store CO2. But these now risk being shut down before CCS is developed, the NAO report said. The CCS competition axed in November was the second cancelled by government, with the first starting in 2007 and ending in 2011. The NAO said there is now “no viable way to achieve deep emissions reductions from the industrial sector in the near future”.

The UK must immediately kickstart an industry to capture and bury carbon emissions in order to save consumers billions a year from the cost of meeting climate change targets, according to a high-level advisory group appointed by ministers. This requires the setting up of a new state-backed company to create the network needed to pipe the emissions into exhausted oil and gas fields under the North Sea, the group said.

Failing to deliver CCS would hugely increase the cost of tackling climate change, according to the government’s official climate advisors, the National Audit Office and the UN’s climate science panel.

CCS could also potentially enable hydrogen to solve the problem of cutting the emissions from the nation’s gas boilers and stoves, currently 25% of all emissions and a major factor in the UK’s imminent failure to meet clean energy targets.

Natural gas can be converted to hydrogen and the CO2 produced buried using CCS. The hydrogen, which produces only water when burned, could then replace the gas in the national grid. This could also provide fuel for hydrogen-powered cars, as well as cutting the significant air pollution caused by gas boilers.

A new report entitled Lowest Cost Decarbonisation for the UK: The Critical Role of CCS, argues that the UK government should drastically rethink its CCS policy, and in effect u-turn again to get back on track with CCS. A cross-party group, headed by Lord Oxburgh, leading geologist and ex-chair of Shell, was invited by previous Secretary of State for Energy and Climate Change Amber Rudd to assess the CCS options in the UK. They conclude that CCS is not only clearly achievable, with all aspects of the supply chain demonstrated, but also potentially cheaper than nuclear or renewable options. The novel nature of the technology however, combined with an insufficient carbon price, means that government, rather than industry, must be the driving force behind the technology’s development.

India

Two world-leading clean energy projects have opened in the south Indian state of Tamil Nadu. An industrial plant is capturing the CO2 emissions from a coal boiler and using the CO2 to make valuable chemicals. The industrial plant appears especially significant as it offers a breakthrough by capturing CO2 without subsidy. Built at a chemical plant in the port city of Tuticorin, it is projected to save 60,000 tonnes of CO2 emissions a year by incorporating them into the chemical recipe for soda ash - otherwise known as baking soda.

The chemical used in stripping the CO2 from the flue gas was invented by two young Indian chemists. They failed to raise Indian finance to develop it, but their firm, Carbonclean Solutions, working with the Institute of Chemical Technology at Mumbai and Imperial College in London, got backing from the UK's entrepreneur support scheme. Their technique uses a form of salt to bond with CO2 molecules in the boiler chimney. The firm says it is more efficient than typical amine compounds used for the purpose. They say it also needs less energy, produces less alkaline waste and allows the use of a cheaper form of steel - all radically reducing the cost of the whole operation.

The IEA believes CCS will have to play a central role in an ambitious, climate-friendly future energy scenario, accounting for one-sixth of required emissions reductions by 2050. IEA analysis has shown that without significant deployment of CCS, more than two-thirds of current proven fossil-fuel reserves cannot be commercialised before 2050 if the increase in global temperatures is to remain below 2 degrees Celsius. Several CCS projects are under construction or in advanced stages of planning. Early 2015 should see the start of operations for another large power-CCS project in Kemper County, Mississippi. Further projects are currently under construction elsewhere in the United States and Canada plus Saudi Arabia and Australia.

FOR SASKPOWER, owner and operator of the retrofitted Boundary Dam Power Unit 3 (BD3) that now incorporates carbon capture and storage (CCS), this event was the culmination of decades of work to continue operating coal-fired power-generating stations, while at the same time mitigating the climate change impact of associated air emissions. The CO2 captured at BD3 is geologically stored at two locations: in an oil reservoir approximately 1.4 kilometres deep at Cenovus’ CO2–EOR operation near Weyburn, Saskatchewan, and in a deep saline aquifer approximately 3.2 kilometres deep at the SaskPower Carbon Storage and Research Centre, located near the Boundary Dam Power Station. The latter geological storage site is the subject of the measurement, monitoring and verification (MMV) activities of the Aquistore Project that is managed by the Petroleum Technology Research Centre in Regina, Saskatchewan. SaskPower had forged ahead with design and construction of the BD3 ICCS retrofit well in advance of GHG Regulations being enacted in Canada, which came into effect on July 1, 2015. This was a strategic and environmentally-responsible decision to ensure continued use of lignite coal reserves in Saskatchewan that could last 250–500 years. The investment in the approx. 120 MW (net) BD3 power unit’s retrofit and carbon capture plant was approximately C$1.467 billion. This report explores the journey that SaskPower made from the 1980s to mid-2015 in pursuit of clean coal power generation. SaskPower pursued various technology options for carbon capture from oxyfuel combustion to amine solvent absorption that ultimately led to the decision to select the commercially unproven CANSOLV amine solvent carbon dioxide capture process. SaskPower then coupled that technology with Shell Cansolv’s proven sulphur dioxide capture process to simplify the capture plant operation and to further reduce emissions.

Boundary Dam held up as first commercial-scale CCS plant and proof that coal-burning is compatible with cutting emissions Canada has switched on the first large-scale coal-fired power plant fitted with a technology that proponents say enables the burning of fossil fuels without tipping the world into a climate catastrophe. The project, the first commercial-scale plant equipped with carbon capture and storage technology, was held up by the coal industry as a real life example that it is possible to go on burning the dirtiest of fossil fuels while avoiding dangerous global warming. Saskatchewan’s state-owned electricity provider is due to cut the ribbon on the $1.3 billion Canadian project on Thursday.

An internal SaskPower briefing note obtained by the NDP suggests the much-celebrated Boundary Dam carbon capture project near Estevan, Sask., has "serious design issues". The note goes on to say the company contracted to engineer, procure, and build the capture facility, SNC-Lavalin "has neither the will or the ability to fix some of these fundamental flaws." The note, dated Sept. 30, 2014, said SaskPower has already paid 97 per cent of the value of the three subcontracts SaskPower had with SNC — $533 million of $549 million. It says at the time SaskPower was withholding $6.5 million in payments from SNC because the Crown corporation was having to pay to correct problems with SNC's work.

OTTAWA — An electrical plant on the Saskatchewan prairie was the great hope for industries that burn coal. In the first large-scale project of its kind, the plant was equipped with a technology that promised to pluck carbon out of the utility’s exhaust and bury it underground, transforming coal into a cleaner power source. In the months after opening, the utility and the provincial government declared the project an unqualified success. But the $1.1 billion project is now looking like a green dream. Known as SaskPower’s Boundary Dam 3, the project has been plagued by multiple shutdowns, has fallen way short of its emissions targets, and faces an unresolved problem with its core technology. The costs, too, have soared, requiring tens of millions of dollars in new equipment and repairs.

Cement production

The manufacture of cement, a constituent of concrete, is responsible for 5.6% of global carbon dioxide (CO2) emissions. 30-40% of these emissions are from thermal fuels (predominantly coal) used to heat the cement kiln, while 60-70% of the emissions are “process emissions” from the breakdown of limestone in a calcination reaction. (A small amount of emissions are also attributable to the generation of electricity used by cement makers.)

After its manufacture, cement naturally sequesters CO2 from the atmosphere in a process called “carbonation.” Carbonation rates vary considerably with concrete properties, which differ by world region. Globally, roughly a third of cement’s process emissions are re-absorbed within the first two years, and over the course of decades, this share rises to 48%. Cement carbonation is relevant on a global scale but has been omitted from national emissions inventories and global estimates.

Modeling of three scenarios finds that capturing 80% of cement’s process emissions (and none of the thermal emissions) by 2050 is sufficient to make cement carbon-neutral, as natural carbonation offsets the remaining emissions. If the thermal fuel supply were to be fully decarbonized by 2050, a process emissions capture rate of 53% achieves carbon-neutral cement. Higher capture rates than these would provide net negative CO2 emissions and the possibility that simply making concrete could reduce atmospheric CO2 concentrations

Cement is one of the world’s most-used building materials, with production reaching 4.3 billion tons/year in 2014 and growing 5 percent to 6 percent annually. Today, it is responsible for 5.6 percent of global carbon dioxide (CO2) emissions and a major contributor to climate change — if the cement industry were a country, it would be the world’s third-largest emitter. To stay below 2 degrees Celsius of global warming, cement’s carbon intensity must be reduced to near-zero as soon as technically feasible.

Fortunately, the right policies and technologies can make cement manufacturing a net climate benefit. During its lifetime and after demolition, cement naturally captures a significant fraction of the CO2 emitted during its manufacture. When this effect is combined with carbon capture and storage (CCS), energy efficiency technologies and biofuels or electrification, cement can remove more CO2 than it adds to the atmosphere.

In the new book "Designing Climate Solutions: A Policy Guide to Low-Carbon Energy," my co-authors and I identify a suite of policies such as carbon pricing, industry efficiency or emissions standards, and government research and development (R&D) support to help ensure the necessary technologies exist and incentivize their use.

Our research shows (PDF) that depending on the extent thermal fuel supply is decarbonized, a CO2 capture rate between 53 percent and 80 percent will make cement carbon-neutral, and higher CCS capture rates achieve net carbon-negative cement. This offers the prospect of a world where simply constructing buildings and infrastructure reduces atmospheric CO2 concentrations and contributes to the fight against climate change.

Technology

Membrane

A new, highly permeable carbon capture membrane developed by scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) could lead to more efficient ways of separating carbon dioxide from power plant exhaust, preventing the greenhouse gas from entering the atmosphere and contributing to climate change. The researchers focused on a hybrid membrane that is part polymer and part metal-organic framework, which is a porous three-dimensional crystal with a large internal surface area that can absorb enormous quantities of molecules.

Non-thermal plasma field

As coal advocates seek to keep their industry viable amid tighter restrictions on carbon emissions, an Illinois researcher says a new spin on a 150-year-old technology might hold the solution. Michael Garvin, an energy expert at the Illinois Institute of Technology, says a technology known as a non-thermal plasma field has shown promise after recent tests – reducing carbon emissions by more than 90 percent – at the Scrubgrass Power Plant in Pennsylvania, which burns dirty “waste coal” to make electricity. The company Carbon Conversion International (CCI) developed technology to pass air emissions through the plasma field to extract carbon dioxide, carbon monoxide, sulfur dioxide and nitrogen oxide. Another byproduct – oxygen – can be fed right back into the combustion chamber. Meanwhile the carbon is concentrated into its nearly elemental form, known as “carbon black,” and sold on the market where it is used for tires, rubber, plastics, printing inks and other applications.

Allam cycle

The Allam cycle uses oxy-combustion with a turbine driven by supercritical CO2 rather than steam.

NET Power, the startup backing the new plant, says it expects to produce emission-free power at about $0.06 per kilowatt-hour. That's about the same cost as power from a state-of-the-art natural gas-fired plant—and cheaper than most renewable energy. The key to its efficiency is a new thermodynamic cycle that swaps CO2 for the steam that drives turbines in conventional plants. Invented by an unlikely trio—a retired British engineer and a pair of technology geeks who had tired of their day jobs—the scheme may soon get a bigger test. If the prototype lives up to hopes, NET Power says, it will forge ahead with a full-scale, 300-megawatt power plant—enough to power more than 200,000 homes—which could open in 2021 at a cost of about $300 million.

North Carolina startup NET Power has found a way to power the transition to a CO2-free future without parting ways with fossil fuels with its pioneering turbine technology.

Piloted at its natural gas plant in Houston, Texas, the technology is powered by carbon dioxide in lieu of the steam used in conventional plants, which is turned into mechanical energy and later electricity. The system draws on the Allam cycle, a process for converting fossil fuels using a single turbine into mechanical power while capturing the resulting water and CO2. This is made possible by using pure oxygen to burn the fuel. The CO2 is separated out in a heat exchanger, then compressed mechanically and a small amount is captured at high pressure, ready for pipeline transmission. The rest of the carbon is reheated and recycled into the combustion unit. The Allam cycle was developed by Rodney Allam in collaboration with 8 Rivers, an investment firm focused on innovative technology.

In addition to eliminating emissions such as CO2, particulate matter, mercury, SOx and NOx, the technology can also eliminate water consumption because it doesn’t require steam for power production.

Due to the high-efficiency design of the turbines, which are one-tenth the size of traditional turbines, NET Power says it will be able to deliver emission-free power at about $0.06 per kilowatt-hour — a major milestone for carbon capture. Carbon capture technologies have traditionally been energy intensive and those costs, using up to 30 percent of a power plant’s energy and as a result driving up the cost of electricity.

Once final testing is complete on its prototype, NET Power will begin operating its plant at full capacity in 2018. The plant is expected to produce enough electricity to power 40,000 homes. If successful, the startup intends to create a 300-megawatt power plant in 2021, which would power more than 200,000 homes. Additionally, the company plans to license the technology in an effort to drive an industry-wide shift.

“This is the biggest thing in carbon capture,” Howard Herzog, a chemical engineer and carbon capture expert at MIT, told Science. “It’s very sound paper. We’ll see if it works in reality. There are only a million things that can go wrong.”

Carbon powder adsorption

Scientists at the University of Waterloo have created a powder that could capture carbon dioxide (CO2) from factories and power plants.

The advanced carbon powder, developed using a novel process in the lab of Zhongwei Chen, a chemical engineering professor at Waterloo, could filter and remove CO2 from emissions at facilities powered by fossil fuels before it is released into the atmosphere with twice the efficiency of conventional materials.

CO2 molecules stick to the surface of carbon when they come in contact with it, a process known as adsorption. Since it is abundant, inexpensive and environmentally friendly, that makes carbon an excellent material to capture CO2, a greenhouse gas that is the primary contributor to global warming.

The researchers, who collaborated with colleagues at several universities in China, set out to improve adsorption performance by manipulating the size and concentration of pores in carbon materials.

The technique they developed uses heat and salt to extract a black carbon powder from plant matter. Carbon spheres that make up the powder have many, many pores and the vast majority of them are less than one-millionth of a metre in diameter.

Once saturated with carbon dioxide at large point sources such as fossil fuel power plants, the powder would be transported to storage sites and buried in underground geological formations to prevent CO2 release into the atmosphere.

Ultramicroporous carbon materials play a critical role in CO2 capture and separation, however facile approaches to design ultramicroporous carbon with controllable amount, ratio and size of pores are still challenging. Herein, a novel strategy to design carbon nanospheres with abundant, uniform, and tunable ultramicroporosity was developed based on an in-situ ionic activation methodology. The adjustable ion-exchange capacity derived from oxidative functionalization was found capable of substantially governing the ionic activation and precisely regulating the ultramicroporosity in the resultant product. An ultrahigh ultramicropore content of 95.5% was achieved for the optimally- designed carbon nanospheres, which demonstrated excellent CO2 capture performances with extremely high capacities of 1.58 mmol g-1 at typical flue gas conditions and 4.30 mmol g-1 at 25 °C and ambient pressure. Beyond that, the CO2 adsorption mechanism in ultramicropore was also investigated through molecular dynamics simulation to guide the pore size optimization. This work provides a novel and facile guideline to engineer carbon materials with abundant and tunable ultramicroporosity towards superior CO2 capture performance, which also delivers great potential in extensive applications such as water purification, catalysis, and energy storage.

Electrical - electroswing adsorber

Chemical engineers at the Massachusetts Institute of Technology have created a new device that can remove carbon dioxide from the air at any concentration. Published in October in the journal Energy & Environmental Science, the project is the latest bid to directly capture CO2 emissions and keep them from accelerating and worsening future climate disasters.

Think of the invention as a quasi-battery, in terms of its shape, its construction and how it works to collect carbon dioxide. You pump electricity into the battery, and while the device stores this charge, a chemical reaction occurs that absorbs CO2 from the surrounding atmosphere — a process known as direct air capture. The CO2 can be extracted by discharging the battery, releasing the gas, so the CO2 then can be pumped into the ground. The researchers describe this back-and-forth as electroswing adsorption.

BECCS

Bioenergy with carbon capture and storage (BECCS) is presented as a pivotal technology in most pathways for limiting global warming to 1.5 or 2°C. However, it is doubtful that BECCS can fulfil this role alone.

BECCS is not a single technology. Understanding the value and challenges associated with each BECCS technology is complex but vital.

Depending on the conditions of its deployment, BECCS may be beneficial but it can also be detrimental to climate change mitigation, due to its lifecycle CO2 balance, energy balance and resource use.

It is challenging to ensure that BECCS delivers timely and sustainable net carbon removal, while also generating energy at an appropriate scale.

Considering these uncertainties and the potential impact on resources, biodiversity and soil health, the scale of BECCS deployment should be limited only to circumstances where it is proven to be beneficial.

Good governance and financial incentives are required to stimulate high-quality BECCS at this limited scale.

Policy makers should be sceptical about a future that is uniquely or heavily reliant on BECCS, and instead prepare for and implement alternative mitigation options as soon as possible.

The Dirty Secret of the World’s Plan to Avert Climate Disaster
by ABBY RABINOWITZ, AMANDA SIMSON
in Wired
on 10 Dec 2017
[article]

IN 2014 HENRIK Karlsson, a Swedish entrepreneur whose startup was failing, was lying in bed with a bankruptcy notice when the BBC called. The reporter had a scoop: On the eve of releasing a major report, the United Nation’s climate change panel appeared to be touting an untried technology as key to keeping planetary temperatures at safe levels. The technology went by the inelegant acronym BECCS, and Karlsson was apparently the only BECCS expert the reporter could find.

Karlsson was amazed. The bankruptcy notice was for his BECCS startup, which he’d founded seven years earlier after an idea came to him while watching a late-night television show in Gothenburg, Sweden. The show explored the benefits of capturing carbon dioxide before it was emitted from power plants. It’s the technology behind the much-touted notion of “clean coal,” a way to reduce greenhouse gas emissions and slow down climate change.

Karlsson, then a 27-year-old studying to be an operatic tenor, was no climate scientist or engineer. Still, the TV show got him thinking: During photosynthesis plants naturally suck carbon dioxide from the air, storing it in their leaves, branches, seeds, roots, and trunks. So what if you grew crops and then burned those crops for electricity, being sure to capture all of the carbon dioxide emitted? You’d then store all that dangerous CO2 underground. Such a power plant wouldn’t just be emitting less greenhouse gas into the atmosphere, it would effectively be sucking CO2 from the air. Karlsson was enraptured with the idea. He was going to help avert a global disaster.

The next morning, he ran to the library, where he read a 2001 Science paper by Austrian modeler Michael Obersteiner theorizing the same idea, which was later dubbed “bioenergy with carbon capture and storage”—BECCS. Karlsson was sold. He launched his BECCS startup in 2007, riding the wave of optimism generated by Al Gore’s first climate change movie. Karlsson’s company even became a finalist in Richard Branson’s Virgin Earth Challenge, which was offering $25 million for a scalable solution for removing greenhouse gases. But by 2014, Karlsson’s startup was a failure. He took the BBC’s call as a sign that he shouldn’t give up.

In the report, the UN’s Intergovernmental Panel on Climate Change—universally known by yet another acronym, IPCC—presented results from hundreds of computer-model-generated scenarios in which the planet’s temperature rises less than 2 degrees Celsius (or 3.6 degrees Fahrenheit) above preindustrial levels, the limit eventually set by the Paris Climate Agreement.

The 2°C goal was a theoretical limit for how much warming humans could accept. For leading climatologist James Hansen, even the 2°C limit is unsafe. And without emissions cuts, global temperatures are projected to rise by 4°C by the end of the century. Many scientists are reluctant to make predictions, but the apocalyptic litany of what a 4°C world could hold includes widespread drought, famine, climate refugees by the millions, civilization-threatening warfare, and a sea level rise that would permanently drown much of New York, Miami, Mumbai, Shanghai, and other coastal cities.

But here’s where things get weird. The UN report envisions 116 scenarios in which global temperatures are prevented from rising more than 2°C. In 101 of them, that goal is accomplished by sucking massive amounts of carbon dioxide from the atmosphere—a concept called “negative emissions”—chiefly via BECCS. And in these scenarios to prevent planetary disaster, this would need to happen by midcentury, or even as soon as 2020. Like a pharmaceutical warning label, one footnote warned that such “methods may carry side effects and long-term consequences on a global scale.”

Indeed, following the scenarios’ assumptions, just growing the crops needed to fuel those BECCS plants would require a landmass one to two times the size of India, climate researchers Kevin Anderson and Glen Peters wrote. The energy BECCS was supposed to supply is on par with all of the coal-fired power plants in the world. In other words, the models were calling for an energy revolution—one that was somehow supposed to occur well within millennials’ lifetimes.

Today that vast future sector of the economy amounts to one working project in the world: a repurposed corn ethanol plant in Decatur, Illinois. Which raises a question: Has the world come to rely on an imaginary technology to save it?

On a sunny day this past October, three dozen people file into a modest, mint-green classroom at Montana State University (MSU) in Bozeman to glimpse a vision of the future. Some are scientists, but most are people with some connection to the land: extension agents who work with farmers, and environmentalists representing organizations such as The Nature Conservancy. They all know that climate change will reshape the region in the coming decades, but that's not what they've come to discuss. They are here to talk about the equally profound impacts of trying to stop it.

Paul Stoy, an ecologist at MSU, paces in front of whiteboards in a powder blue shirt and jeans as he describes how a landscape already dominated by agriculture could be transformed yet again by a different green revolution: vast plantations of crops, sown to sop up carbon dioxide (CO2) from the sky. "We have this new energy economy that's necessary to avoid dangerous climate change, but how is that going to look on the ground?" he asks.

In 2015, the Paris climate agreement established a goal of limiting global warming to "well below" 2°C. In the most recent report of the Intergovernmental Panel on Climate Change, researchers surveyed possible road maps for reaching that goal and found something unsettling. In most model scenarios, simply cutting emissions isn't enough. To limit warming, humanity also needs negative emissions technologies (NETs) that, by the end of the century, would remove more CO2 from the atmosphere than humans emit. The technologies would buy time for society to rein in carbon emissions, says Naomi Vaughan, a climate change scientist at the University of East Anglia in Norwich, U.K. "They allow you to emit more CO2 and take it back at a later date."

Whether that's doable is another question. Some NETs amount to giant air-purifying machines, and many remain more fiction than fact. Few operate at commercial scales today, and some researchers fear they offer policymakers a dangerous excuse to drag their feet on climate action in the hopes that future inventions will clean up the mess. "In many ways, we're saying we expect a bit of magic to occur," says Chris Field, a climate scientist at Stanford University in Palo Alto, California, who instead favors drastic emissions reductions. Others say we no longer have a choice—that we have dallied too long to meet the Paris targets solely by tightening our belts. "We probably need aggressive and immediate mitigation, plus some negative emissions," says Pete Smith, a soil scientist and bioenergy expert at the University of Aberdeen in the United Kingdom.

One particular technology has quietly risen to prominence—thanks to global models—and it is the one on tap in Bozeman. The idea is to cultivate fast-growing grasses and trees to suck CO2 out of the atmosphere and then burn them at power plants to generate energy. But instead of being released back into the atmosphere in the exhaust, the crops' carbon would be captured and pumped underground. The technique is known as bioenergy with carbon capture and storage, or—among climate wonks—simply as BECCS.

Illinois ethanol plant

Negative emissions tested at world’s first major BECCS facility
by Carbon Brief
on 31 May 2016
[article]

Decatur, Illinois, is a city built on corn. At the centre of its economy are two giant agribusinesses, Tate & Lyle and Archer Daniels Midland (ADM), which together grind thousands of bushels a day into syrups, sweeteners, ethanol fuel and other useful products. Thanks to the second of these companies, Decatur is also a city that is built on CO2 — literally. For the past nine years, ADM has been part of an ongoing experiment to capture the emissions from its ethanol plant and trap it in the layer of sandstone that lies beneath the Illinois corn belt.

The quest to capture and store carbon – and slow climate change — just reached a new milestone
by Chris Mooney
in Washington Post
on 10 April 2017
[article]

A new large-scale technology has launched in Decatur, Illinois that, by combining together corn-based fuels with the burial of carbon dioxide deep underground, could potentially result in the active removal of greenhouse gases from the atmosphere.

Limitations: planetary boundaries

Under the Paris Agreement, 195 nations have committed to holding the increase in the global average temperature to well below 2 °C above pre industrial levels and to strive to limit the increase to 1.5 °C (ref. 1). It is noted that this requires "a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of the century"1. This either calls for zero greenhouse gas (GHG) emissions or a balance between positive and negative emissions (NE)2,3. Roadmaps and socio-economic scenarios compatible with a 2 °C or 1.5 °C goal depend upon NE via bioenergy with carbon capture and storage (BECCS) to balance remaining GHG emissions4–7. However, large-scale deployment of BECCS would imply significant impacts on many Earth system components besides atmospheric CO2 concentrations8,9. Here we explore the feasibility of NE via BECCS from dedicated plantations and potential trade-offs with planetary boundaries (PBs)10,11 for multiple socio-economic pathways. We show that while large-scale BECCS is intended to lower the pressure on the PB for climate change, it would most likely steer the Earth system closer to the PB for freshwater use and lead to further transgression of the PBs for land-system change, biosphere integrity and biogeochemical flows.

This big new idea for stopping climate change would cause even bigger problems, scientists say
by Chris Mooney
in Washington Post
on 22 Jan 2018
[article]

scientists argue that deploying BECCS technology on the scale needed to address the problem would use up massive amounts of water, fertilizer and land. That would probably lead to large environmental problems or even destabilize key planetary systems, wrote Vera Heck of the Potsdam Institute for Climate Impact Research and three colleagues.

Direct Air Capture

Climeworks / Iceland & Switzerland

Unfortunately, it's no longer enough to cut CO2 emissions to avoid further global temperature increases. We need to remove some of the CO2 that's already there. Thankfully, that reversal is one step closer to becoming reality. Climeworks and Reykjavik Energy have started running the first power plant confirmed to produce "negative emissions" -- that is, it's removing more CO2 than it puts out. The geothermal station in Hellsheidi, Iceland is using a Climeworks module and the plant's own heat to snatch CO2 directly from the air via filters, bind it to water and send it underground where it will mineralize into harmless carbonates.

Just like naturally forming carbon deposits, the captured CO2 should remain locked away for many millions of years, if not billions. And because the basalt layers you need to house the CO2 are relatively common, it might be relatively easy to set up negative emissions plants in many places around the world.

As always, there are catches. The Hellsheidi plant capture system is still an experiment, and the 50 metric tonnes of CO2 it'll capture per year (49.2 imperial tons) isn't about to offset many decades of fossil fuel abuse. There's also the matter of reducing the cost of capturing CO2. Even if Climeworks improves the efficiency of its system to spend $100 for every metric ton of CO2 it removes, you're still looking at hundreds of billions of dollars (if not over a trillion) spent every year to achieve the scale needed to make a difference. That will require countries to not only respect climate science, but care about it enough to spend significant chunks of their budgets on capture technology.

Switzerland-based Climeworks is now allowing anyone in the world the opportunity to turn their travel emissions into stone.

The solution that Climeworks has created works to address the three issues with carbon capture and sequestration all at the same time — by building smaller capture plants in locations that have both a power source and either a use for the carbon or the ability to immediately sequester it, Climeworks has created what they believe is a super climate-efficient process that captures more than 90% of the CO2 from air and permanently sequesters it underground … even including the footprint for the manufacture of the material to make their scrubbers.

Climeworks believes that they can do this at a large scale at a competitive cost — currently, their cost is about $600 per ton, but they expect that to drop to $200 in the next three or four years, and hit a long term goal of less than $100 per ton in the next decade. Their goal is to capture 1% of the world’s emissions by 2025, an extremely ambitious timeline.

To do that, they need markets for their product. To that point, Climeworks announced a partnership with Coca-Cola HBC to use Climeworks-captured carbon in Coke’s carbonated drinks, starting with Valser sparking water. While Coca Cola uses a small amount of CO2 every year — an estimate by Dr. Roy Spencer for this article from CNSNews in 2008 placed it at 4,000 tons of carbon dioxide a day worldwide — last summer Coke experienced a shortage of CO2 in Europe.

Turns out the food and beverage industry really relies on CO2, with over 10 million tons being used in the industry worldwide. With Climeworks, companies could have their own, potentially in-house carbon production plants, eliminating future CO2 shortage concerns.

Additionally, Climeworks has projects in the works to use their captured CO2 in greenhouses and in renewable methane, pushing efforts to use (or perhaps we should say, re-use) captured CO2 for industrial uses.

Which brings us to today — Climeworks now offers the opportunity to sequester part or all of your emissions! They have three options, 85kg per year for $96, 255kg per year for $288, or 600kg per year at $660.The carbon capture plants are running at a geothermal power plant in Iceland and sequestering the carbon underground into basaltic rock, turning it into stone within a few years.

While this is expensive — the math works out to $1,100 per metric ton of carbon removed — I signed up for the 85kg rate.

There are cheaper methods out there, (CoolEffect is one I’d suggest checking out), but I’m hoping that with some more support, Climeworks and direct air carbon capture can help.

Antarctic

A modest proposal for sequestration of CO2 in the Antarctic
by Judith Curry
in Climate Etc
on 24 Aug 2012
[article]

A scientific plan is presented that proposes the construction of carbon dioxide (CO2) deposition plants in the Antarctic for removing CO2 gas from Earth’s atmosphere. The Antarctic continent offers the best environment on Earth for CO2 deposition at 1 bar of pressure and temperatures closest to that required for terrestrial air CO2 “snow” deposition—133 K. This plan consists of several components, including